1. Field of the Invention
This invention generally relates to optical devices with stabilizing feedback and more specifically to optical devices having several stable states characterized by respectively different colors.
2. Description of the Prior Art
A seven-segment display employing optical feedback to stabilize monochromatic light sources is disclosed in U.S. Pat. No. 3,911,423 issued Oct. 7, 1975 to Horst Arndt et al.
A multicolor semiconductor lamp comprising a plurality of light emitting diodes for emitting light of respectively different colors is disclosed in U.S. Pat. No. 3,875,456 issued Apr. 1, 1975 to Tsuyoshi Kano et al. The light emitting diodes are closely adjacent and covered by a layer of light scattering material to provide an appearance of a single light source.
An optical device capable of exhibiting more than two stable states characterized by respectively different colors is unknown.